The real cause of a common stroke may have been missed for decades

New research indicates that the primary cause of lacunar stroke is linked to widening of small brain arteries, rather than the buildup of fatty plaques in large arteries, as previously believed. This finding challenges decades of medical assumptions and could lead to new treatment strategies for a common and disabling type of stroke.

Scientists from the University of Edinburgh and international collaborators analyzed MRI scans of 229 stroke patients, finding that artery widening was strongly associated with lacunar strokes and progression of small vessel disease. In contrast, narrowing of large arteries was not linked to this stroke type or to subsequent brain damage.

The study revealed that patients with enlarged arteries were over four times more likely to have experienced a lacunar stroke. These patients also showed more severe small vessel disease, faster progression of brain damage, and a higher incidence of silent strokes—small, symptomless brain injuries caused by interrupted blood flow.

Importantly, standard treatments like aspirin and antiplatelet drugs did not prevent silent strokes in over a quarter of participants, underscoring the need for targeted therapies addressing microvascular damage. Ongoing trials, such as LACI-3, are testing drugs like cilostazol and isosorbide mononitrate to protect small vessels and reduce stroke recurrence and cognitive decline.

Impact of Vessel Widening on Stroke Prevention

This discovery shifts the focus from large artery plaque buildup to microvascular health, explaining why traditional treatments often fail in preventing lacunar strokes. It opens new avenues for targeted therapies that could significantly reduce disability and cognitive decline associated with this common stroke subtype.

Previous Assumptions About Stroke Causes

For decades, the prevailing view has been that fatty plaques in large arteries lead to strokes, including lacunar types. This assumption shaped prevention strategies like antiplatelet therapy. However, lacunar strokes, which account for a significant portion of ischemic strokes, have remained difficult to prevent effectively, prompting researchers to investigate alternative causes.

Recent imaging studies have begun to suggest that small vessel disease, characterized by changes within the tiny arteries of the brain, plays a critical role. The new research confirms that artery widening, rather than narrowing, correlates with the development and progression of lacunar strokes, challenging longstanding paradigms.

“This study provides strong evidence that lacunar stroke is caused by disease of the small vessels within the brain, not by fatty blockage of larger arteries.”

— an anonymous researcher

Unanswered Questions About Microvascular Damage

While the link between artery widening and lacunar stroke is strong, it remains unclear whether specific interventions can reverse or prevent vessel enlargement. The long-term effectiveness of drugs like cilostazol and isosorbide mononitrate in microvascular protection is still under investigation, and more research is needed to confirm causality and optimal treatment strategies.

Next Steps in Research and Treatment Trials

Researchers are continuing to evaluate targeted therapies in clinical trials such as LACI-3, aiming to develop effective drugs that address small vessel disease directly. Further studies will clarify whether early detection of vessel widening can improve stroke prevention and reduce cognitive decline. Additionally, understanding the mechanisms behind artery enlargement may lead to new diagnostic tools and personalized treatment plans.

Key Questions

How does this discovery change stroke prevention?

It shifts the focus from large artery plaque buildup to the health of small brain vessels, potentially leading to more effective, targeted therapies for lacunar stroke prevention.

Are current treatments effective for this type of stroke?

Standard treatments like aspirin have limited success in preventing lacunar strokes, which may be caused by vessel widening rather than blockages. New therapies are being tested to better address this underlying cause.

What are silent strokes, and why are they important?

Silent strokes are small brain injuries without noticeable symptoms but can accumulate over time, contributing to cognitive decline and dementia. They are more common in patients with vessel widening.

Will this discovery lead to new medications?

Yes, ongoing trials are testing drugs aimed at protecting small vessels, which could improve prevention and reduce long-term disability from lacunar strokes.

When can patients expect new treatments to become available?

It is too early to specify, but ongoing clinical trials like LACI-3 are expected to provide answers within the next few years, potentially leading to new treatment options.

Source: rss